UML22 — AssociationClass

The text says that a non-navigable end of an association class is an attribute of that association class. "When a property is owned by a class it represents an attribute." [7.11.4] "AssociationClass is both an Association and a Class." [7.16.1] "When a property is owned by an association it represents a non-navigable end of the association." [7.11.2] This is good, is as expected, and is consistent with both the object and the relational theories of modelling. It is said that the drawings tell a different story. If so, they should be corrected. There is no practical advantage to requiring that the non-navigable ends of an association class are not attributes of that class. On the contrary, such a requirement is unexpected and will be confusing.

Discussion
The issue is obsolete. The text in 11.5.3 clearly states that the ownedEnds of an AssociationClass are not
attributes.
Disposition: Closed - No Change